A variety of means have heretofore been devised for correcting and compensating for misalignment and misplacement errors in the mounting of structures to a support surface. Such errors, which can produce undesirable stresses in the mounting mechanisms and the structures themselves, frequently arise in the mounting of structures which have a plurality of "legs", since such "legs" may be of unequal length as well as being oriented at angles to the mounting surface which are other than desired. With metallic structures, aside from errors in critical manufacturing measurements and specifications, the problem is sometimes caused by warpage resulting from welding during fabrication. In other instances aside from stress problems, it may be necessary to adjust the overall height of the structure which is mounted.
Some of the previous methods which have been used to correct misalignment and misposition problems include the use of multiple spacers, multiple shims, and screw jacks. In general, however, these methods are useful in only the simple problem cases. In more complex situations, such as in the mounting of structures having multiple "legs" or attachment points, these previous methods are oftentimes inadequate, very difficult, time consuming, and sometimes very costly.
The use of shims and spacers is usually a "trial and error" method requiring multiple, repetitive measurements to come close to eliminating misalignment or misposition of the "legs". In some cases these shims and spacers can be difficult to permanently fix in a desired position. If the problem is severe enough, the use of shims and spacers could induce loading problems on the apparatus used to fasten the "legs" to the mounting surface. On the other hand, the use of jacks is mostly sufficient for situations where the problems arise only from the differences in the lengths of the "legs". However, should there be any angular misalignment in the "legs", such misalignment will result in instability of the screw jack as well as induce a bending moment on the jack.
In the prior art, U.S. Pat. No. 4,690,265 discloses a clamping device for setting a detail to a fixture base. The device includes a clamping means comprising spring washers and a clamp nut disposed about the upper threaded end portion of an elongate member which is provided with a flange intermediate the threaded portions whereby the clamping means is adapted to clamp a structure to be mounted against the flange. The device provides for single load line jacking but lacks precision alignment and positioning capability because of its reliance on the deformation and oversizing of parts.
U.S. Pat. No. 4,061,298 discloses an aligning device for a machine in which a support body for a machine pedestal is guided in a threaded portion of a base member. The support body and a central tension rod are interconnected through an entrainment device. The support body can be vertically adjusted to raise the machine. This device requires access to the top of the mechanism during adjustment and cannot be readily adjusted after clamping to the object to be mounted.
U.S. Pat. No. 3,239,169 discloses a motor support which is vertically adjustable and includes a threaded vertical post and screw mechanism. The motor support does not provide for angular adjustment and has no means to prevent backdrive of the screw mechanism.
U.S. Pat. No. 4,632,356 discloses a vertically adjustable mounting device with a threaded spindle, but does not provide for angular alignment or adjustment means.